Serum paraoxonase polymorphism in three populations of southeast Asia.

Serum paraoxonase hydrolyzes paraoxon, the principal metabolite of the insecticide parathion. Serum paraoxonase is polymorphic and controlled by two codominant alleles - PON*A and PON*B representing low and high activity, respectively. Three populations of southeast Asia comprising 194 Chinese, 159 Filipinos and 73 Dravidian Indians were investigated for serum paraoxonase polymorphism. The frequency of PON*B was found to be 0.14 in the Chinese, 0.04 in the Filipinos and 0.18 in Dravidian Indians. The distribution of the PON phenotypes was at Hardy-Weinberg equilibrium in all the three populations studied.     

Paraoxonase 1 gene polymorphism 192Q/R in old men and long-livers from Tatars ethnic group

Comparison in genotype and allele frequencies of people groups of younger (from 1 till 20 years), middle (21-55 years), elderly (56-74 years), senile (75-89 years) age and long-livers (90-109 years) have been performed (only 1116 person) with the purpose of analysis of molecular-genetic bases of ageing and longevity of the person. Allele variants of PON1 gene have been identified by polymerase chain reaction in a combination with restriction analysis. In the general sample of Tatars genotypes PON1*Q/*Q, PON1*Q/*R and PON1*R/*R are revealed with frequencies of 46.15, 44.35 and 9.5%, alleles PON1*Q and PON1*R are found with frequencies of 68.32 and 31.68% accordingly. Statistically significant distinctions on frequencies of genotypes and alleles between separate age groups are found. It has appeared, that frequency of PON1*R allele (28.46%) is lowered among old men in comparison with those among persons of younger age (37.42%, P = 0.009). However essentially above in group of long-livers, than in group of old men, frequencies allele PON1*R (P = 0.005) and genotype PON1*R/*R (P = 0.01).     

Genetic variants of the paraoxonases (PON1 and PON2) in the Chilean population

We estimated the frequencies of PON1 and PON2 variants (linked genes) in two hospital samples taken from the northern (San José Hospital, SJH) and eastern (Clínica Las Condes, CLC) parts of Santiago, Chile, using the polymerase chain reaction followed by restriction endonuclease digestion. The two hospital samples have different degrees of Amerindian admixture (SJH, 34.5%; CLC, 15.9%), which is reflected in the observed frequencies of the PON1 *B allele (SJH, 43.1%; CLC, 33.7%) and the PON2*S allele (SJH, 86.3%; CLC, 77.6%); both allele frequencies are significantly different between samples. The frequencies of the combined PON1-PON2 genotypes *A/*B-*C/*C, *A/*B-*S/*S, and *B/*B-*S/*S and of the haplotypes PON*A,C and PON*B,S were significantly different between the SJH and CLC groups. None of the genotype frequencies deviated significantly from those predicted by the Hardy-Weinberg equation. No linkage disequilibrium was found between the PON1 alleles and any of the PON2 alleles in either group (all p > 0.05). In our samples 38.52% (SJH) and 26.25% (CLC) of chromosomes must have the haplotype PON*B,S, presumed to be related to the risk of coronary artery disease. Twenty-four of 193 (12.4%) SJH individuals and 7 of 122 (5.7%) CLC individuals were homozygotes for this haplotype. Finally, our data indicate ethnic-group-dependent genetic differences in the vulnerability to toxic organophosphorus.     

A preliminary study of human paraoxonase and PON 1 L/M55–PON 1 Q/R 192 polymorphisms in Turkish patients with coronary artery disease

Paraoxonase 1 (PON 1) is a high‐density lipoprotein (HDL)‐associated enzyme with antioxidant function protecting low‐density lipoprotein (LDL) from oxidation. PON 1 has two amino acid polymorphisms in coding region; L/M 55 and Q/R 192. These polymorphisms modulate paraoxonase activity of the enzyme. PON 1 activity decreases in coronary artery disease (CAD). In the present study, distribution of PON 1 L/M 55 and Q/R 192 polymorphisms and the effect of these polymorphisms on the activities of PON 1, and on the severity of CAD in 277 CAD (+) patient and 92 CAD (?) subjects were examined. PON 1 L/M 55 and Q/R 192 genotypes were determined by PCR, RFLP and agarose gel electrophoresis techniques. Genotype distributions and allele frequencies for PON 1 Q/R 192 polymorphism were not significantly different between controls and CAD (+) patient group (p > 0.05), but in genotype and allele distribution of PON 1 L/M55 polymorphism, there was significantly difference among groups (p < 0.05). Genotype distributions for both polymorphisms were not significantly different between subgroups of single‐vessel disease (SVD), double‐vessel disease (DVD) and triple‐vessel disease (TVD). Serum PON 1 activity was lower in CAD (+) group than in controls and this was also statistically significant (p < 0.001). In both groups, the highest PON activities were detected in LL and RR genotypes. In summary, our results suggest that there is an association between the PON 1 L/M 55 polymorphism of paraoxonase and CAD in Turkish patients but not with PON 1 Q/R 192 polymorphism. However, it is hard to correlate these polymorphisms and severity of CAD. Copyright © 2009 John Wiley & Sons, Ltd.     

DNA polymorphisms in two paraoxonase genes (PON1 and PON2) are associated with the risk of coronary heart disease.

A common polymorphism at codon 192 in the human paraoxonase (PON) 1 gene has been shown to be associated with increased risk for coronary heart disease (CHD) in Caucasian populations. However, these findings have not been reported consistently in all Caucasian and non-Caucasian populations, suggesting that this is not a functional mutation but may mark a functional mutation present in either PON1 or a nearby gene. Recently, two other PON-like genes, designated "PON2" and "PON3," have been identified, and they are linked with the known PON1 gene on chromosome 7. Identification of additional polymorphisms in the PON-gene cluster may help to locate the functional polymorphism. In this report, we describe the existence of a common polymorphism at codon 311 (Cys-->Ser; PON2*S) in the PON2 gene, as well as its association with CHD alone and in combination with the PON1 codon 192 polymorphism in Asian Indians. The frequency of the PON2*S allele was significantly higher in cases than in controls (.71 vs. .61; P=.016). The age- and sex-adjusted odds ratio (OR) was 2.5 (95% confidence interval &sqbl0;95% CI&sqbr0;=1.8-3.1; P=.0090) for the PON2*S allele carriers. Further stratification of the PON2*S association, on the basis of the presence or absence of the PON1*B allele, showed that the CHD risk associated with the PON2*S allele was confined to PON1*B-allele carriers. Likewise, the PON1*B-allele risk was present only among PON2*S carriers. Age- and sex-adjusted ORs for the PON2*S and PON1*B were 3.6 (95% CI=2.6-4.6; P=.011) and 2.9 (95% CI=2.4-3.5; P=.0002) among the PON1*B and PON2*S carriers, respectively. Our data indicate that both polymorphisms synergistically contribute to the CHD risk in this sample and that this genetic risk is independent of the conventional plasma lipid profile.     

Plasma paraoxonase polymorphism: a new enzyme assay, population, family, biochemical, and linkage studies.

Plasma paraoxonase hydrolyzes paraoxon, the principal metabolite of the insecticide parathione. A genetic polymorphism for enzyme activity has been previously demonstrated. We describe a new assay based on the differential inhibition by EDTA of plasma paraoxonase from persons with the high-activity allele (PX*H) that suggests a trimodality of activity levels in population studies. The gene frequency of the low activity allele (PX*L) in 531 Seattle blood donors of European origin was .7207. Family studies were consistent with codominant autosomal inheritance of two alleles, PX*L (low) and PX*H (high), coding for products with different activity levels. Biochemical measurements of sera from presumed homozygotes for the two different alleles revealed minor physicochemical differences suggestive of a structural difference between the allelic products. No evidence for linkage of the paraoxonase locus with any of 19 polymorphic markers would be detected.     

Investigating paraoxonase-1 gene Q192R and L55M polymorphism in patients with renal cell cancer

Increased oxidative stress can help promote carcinogenesis, including development of renal cell carcinoma. The enzyme protects low-density lipoproteins from oxidation and can be a factor in this process. PON1 Q192R and L55M paraoxonase gene polymorphisms were assessed in 60 renal cell carcinoma patients and 60 healthy controls. Genotypes were examined by PCR; the restriction enzyme AlwI was used to examine the Q192R polymorphism and Hsp92II for the L55M polymorphism. Significant differences in the PON1 Q192R polymorphism were found between patients and controls. The Q allele was more frequent in the patient group than in controls, while the R allele was more frequent in the control group. No significant differences were found in the L55M polymorphism. Additionally, there were no significant differences in L and M allele frequencies. We conclude that the R allele may protect against renal cell carcinoma.     

Preliminary observations of MHC class I A region polymorphism in three populations of Chinese-origin rhesus macaques

Rhesus macaques are an animal model for the study of a variety of human diseases. The Chinese rhesus macaques have been widely used in biomedical research in recent years. However, the polymorphism of major histocompatibility complex (MHC) class I A region among different local populations of Chinese rhesus macaques has never been investigated. In this study, we identified 46 Mamu-A alleles by cDNA cloning and sequencing on a cohort of 53 Chinese rhesus monkeys including Zhiming, Chuanxi, and Fujian populations, of which 5 were first reported in rhesus monkeys. The frequencies of alleles were identified for each population. The result suggests that the repertoire of allelic variants of MHC class I A region found in different populations of Chinese macaques is largely non-overlapping. The frequencies of alleles and the popular allele are also different for different populations. PCR-SSP experiment further confirms the different frequencies of two alleles, Mamu-A*026:01 and Mamu-A*022:01, in additional 99 Zhiming monkeys and 191 Chuanxi monkeys. Our findings have important practical implications in that the origin of the individuals and the genetic polymorphism of the monkeys need to be considered at the level of local populations for Chinese rhesus monkeys in biomedical research. Further immunogenetic work is needed to investigate the MHC polymorphism among different populations of Chinese rhesus macaques and to reveal the functional implication of such polymorphism and disease outcome correlations.     

Five polymorphisms of the apolipoprotein B gene in healthy Bulgarians

Five APOB polymorphisms (I/D in the promoter region, XbaI [codon 24881, MspI [codon 3611], EcoRI [codon 41541, and 3' VNTRs) were studied in a population sample of 147 healthy normolipemic Bulgarians. For all biallelic loci, the observed genotype distributions do not deviate from Hardy-Weinberg equilibrium. In Bulgaria the insertion allele and the MspI+ allele of APOB presented the highest allelic frequencies (0.793 +/- 0.024 and 0.959 +/- 0.012, respectively) among the European population groups studied so far. The allele frequencies of the other two biallelic polymorphisms (XbaI and EcoRI) found in the Bulgarian population are similar to those previously described in other Caucasian populations. Analysis of the 3' VNTR polymorphism revealed 11 different alleles. Like studies in other Caucasian populations, this study found bimodal allele-size distribution and a high level of heterozygosity. The frequency of allele *31 (0.162 +/- 0.022) among Bulgarians is higher than that of any other European population group studied so far. Genetic distances between Bulgarians and each of six populations from southeastern Europe for which 3' VNTR allele frequencies are available showed an increase in the order: Albanians相似文献   

Association between paraoxonase-1 gene Q192R and L55M polymorphisms and risk of gastric cancer: A case-control study from Iran

The aim of the present study was to examine the relation between two paraoxonase1 (PON1) polymorphisms, Q192R and L55M and susceptibility to gastric cancer in an Iranian population. In this case-control study the PON1 polymorphisms were assessed in 90 gastric cancer patients and 90 healthy controls by polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) method. Regarding PON1 Q192R polymorphism, a significant increase in the R allele in the patient group compared with the controls (p value?=?0.0006) While the Q allele was more frequent in the control group. No significant difference was found in the genotype or allele frequency of the L55M polymorphism between healthy individuals and patients with gastric cancer. Our results demonstrated the protective effect of Q allele against gastric cancer.     

Genetic polymorphism of alpha 2HS-glycoprotein.

A genetic polymorphism of the human serum glycoprotein, alpha 2HS-glycoprotein, can be recognized using isoelectric focusing in polyacrylamide, followed by silver-stain immunofixation. In a North American Caucasian population, two common alleles and one rare allele have been recognized, with frequencies as follows: AHSG*1: .6419, AHSG*2: .3535, and AHSG*3: .0046; polymorphism information content (PIC): .36. A black population from various islands of the Caribbean has the two most common alleles, plus a variant (B) not found in the white population. Allele frequencies in the blacks were: AHSG*1: .6901, AHSG*2: .2606, AHSG*B: .0493; PIC: .396. Family studies confirmed the allele designations. Alleles in both populations were in Hardy-Weinberg equilibrium. This polymorphism will be useful as a marker on chromosome 3q and for forensic studies. The serum concentration associated with AHSG*1 may be somewhat greater than that associated with AHSG*2. Differences between the allele products remained after removal of sialic acid from the glycoprotein with neuraminidase. The silver-stain immunofixation technique used for this polymorphism has wide application for the study of polymorphisms where the protein is present in low concentration or where only low titer antiserum is available.     

Analysis of Genetic Polymorphism of Deoxyribonuclease I in Ovambo and Turk Populations Using a Genotyping Method

Deoxyribonuclease I (DNase I) polymorphism has been used as a valuable marker in genetic and clinical investigations. Six codominant alleles are known for DNase I, DNASE1*1, *2, *3, *4, and the recently discovered alleles *5 and *6. To detect these two new alleles, we added a new DNase I genotyping method based on both an allele-specific amplification and mismatched polymerase chain reaction (PCR). These methods were used to examine the distribution of DNase I genotypes in unrelated individuals from bloodstains of Ovambo and Turkish populations. The DNASE1*1 allele was found to be most dominant in the Ovambos. In contrast, Turks showed the highest allele frequency for DNASE1*2. This study is the first to demonstrate that there is a certain genetic heterogeneity in the worldwide distribution of DNase I polymorphism using the genotyping method of human DNase I polymorphism with PCR.     

CYP2A6 polymorphism reveals differences in Japan and the existence of a specific variant in Ovambo and Turk populations

CYP2A6 is a polymorphic enzyme, and CYP2A6 genotype has been shown to be associated with smoking habits and lung cancer. We investigated CYP2A6 polymorphism in Japanese from four different geographic areas of Japan and in the Ovambo and Turk populations. Using two polymerase chain reaction restriction fragment length polymorphisms (PCR-RFLPs), we identified the functionally important variants of CYP2A6: *1A, *1B, *1F, *1G, *4A, and *4D. In the Japanese population the highest frequencies of the CYP2A6*1A allele were observed in subjects from the Fukuoka (Kyushu Island) and Ehime (Shikoku Island) prefectures, whereas subjects in Shimane and Tottori (both located on the Japan Sea side of Honshu Island) showed the highest frequencies of the CYP2A6*1B allele. In the Tottori and Shimane groups no subject was homozygous for the CYP2A6*4A allele, a whole gene deletion type that is prevalent among Asians. In the Ovambo and Turk populations the CYP2A6*1A allele was predominant. Furthermore, two alleles undetected in the Japanese were observed in these latter two ethnic groups: CYP2A6*1G was found solely in the Ovambos, and CYP2A6*1F was found solely in the Turks. The present study is the first to show interprefecture differences in CYP2A6 polymorphism in Japanese who live in relatively close but distinct geographic areas; this is also the first study to evaluate CYP2A6 variations among these Japanese and the Ovambo and Turk populations. The distribution results of these alleles could help to define the true significance of CYP2A6 polymorphism as a genetic susceptibility marker in worldwide populations.     

Role of genetic polymorphism of human plasma paraoxonase/arylesterase in hydrolysis of the insecticide metabolites chlorpyrifos oxon and paraoxon

Plasma paraoxonase is a polymorphic enzyme that hydrolyzes paraoxon, the neurotoxic, active metabolite of the insecticide parathion. This enzyme is specified by at least two alleles with frequencies of about .7 and .3 among Caucasoid populations. A specific assay was developed that measured the activity of human plasma paraoxonase without interference from serum albumin which contributes significantly to the hydrolytic breakdown of paraoxon at the high pH values used in many previous assays. There was an 11-fold variation in paraoxonase activities, and the population distribution was at least bimodal. However, this specific assay did not improve the discrimination between the three genetic classes: (1) homozygotes for the low-activity allele, (2) heterozygotes, and (3) homozygotes for the high-activity allele. Chlorpyrifos oxon--the neurotoxic metabolite of the organophosphorus insecticide chlorpyrifos (Dursban)--was hydrolyzed by the same plasma fraction that hydrolyzed paraoxon. There was only four- to fivefold variability in enzyme activity, and the population distribution was unimodal. Homozygotes for low paraoxonase activity ranged over almost the entire spectrum of chlorpyrifos oxonase activity. Possible differences in susceptibility to chlorpyrifos toxicity therefore are unlikely to be predicted by the paraoxonase genotype alone. The ratio of paraoxonase over that of chlorpyrifos oxonase provided an excellent method for genetic typing of the paraoxonase polymorphism, as did the substitution of phenylacetate for chlorpyrifos as the substrate.     

Polymorphism 192Q/R of the paraoxonase 1 gene in elderly men and long-lived people of the Tatar ethnic group

To study the molecular genetic basis of human aging and longevity, the allele and genotype frequencies of the 192Q/R polymorphism of PON1 were compared for ethnic Tatars of the younger (1–20 years), middle (21–55 years), elderly (56–74 years), senile (75–89 years), and long-lived (90–109 years) age groups (in total, 1116 people). The PON1 alleles were identified using PCR and restriction enzyme analysis. In the total samples, the frequencies of genotypes Q/Q, Q/R, and R/R were 46.15, 44.35, and 9.5%, respectively, and the frequencies of alleles Q and R were 68.32 and 31.68%, respectively. Some age groups significantly differed from each other in allele and genotype frequencies. The frequency of allele R in the senile group (28.46%) was significantly lower than in the younger group (37.42%, P = 0.009). However, the long-lived displayed significantly higher frequencies of allele R (P = 0.005) and genotype R/R (P = 0.01) as compared with the senile group.     

The determination of Q192R polymorphism of paraoxonase 1 by using non-toxic substrate p-nitrophenylacetate

CONTEXT:

The human serum paraoxonase 1 (PON1) is calcium-dependent esterase and associates with the high density serum lipoproteins. PON1 plays a major role in oxidation of high density lipoprotein and low density lipoprotein and prevention of atherogenesis in coronary heart disease. PON1Q and R allele hydrolyses number of substrates like paraoxon (PO) (diethyl p-nitrophenyl phosphate) and phenylacetate.

AIMS:

The aim of the study is to the determination of Q192R polymorphism of PON1 by using non-toxic substrate p-nitrophenylacetate and compares it with the phenotype determined by using PO as substrate.

MATERIALS AND METHODS:

The study group consists of 60 healthy normal patients. Paraoxonase activity was measured using the procedure described by Eckerson (Reference method) and for phenotyping; the ratio of hydrolysis of PO in the presence of 1 M NaCl (salt-stimulated PON1, SALT) to the hydrolysis of phenylacetate (PA) is calculated. In new method (Haagen et al.) arylesterase activity measured using p-nitrophenylacetate and for phenotyping arylesterase, the ratio of inhibition of enzymatic hydrolysis of p-nitrophenylacetate (substrate) by phenyl acetate to non-inhibited hydrolysis of p-nitrophenylacetate (inhibited arylesterase activity (IA-IA₀)/non-inhibited arylesterase activity (NIA).

RESULTS:

It was found that paraoxonase activity is trimodally distributed in both the methods. There is no significant difference in the distribution of PON1 phenotypes of both reference method and new method being frequencies 0.946 and 0.376 respectively and there was no significant difference for phenotypic polymorphism for an individual by both methods (χ²= 0.15 and P = 0.9262).

CONCLUSION:

The Q192R polymorphism of PON1 by using non-toxic substrate p-nitrophenylacetate showed trimodal distribution of QQ (homozygous), QR (heterozygous), and RR (homozygous) phenotype and it is comparable with reference method. This method can be used for PON1 phenotype in different pathological and complex disease conditions.     

Genetic studies of human apolipoproteins. X. The effect of the apolipoprotein E polymorphism on quantitative levels of lipoproteins in Nigerian blacks.

Human apolipoprotein E exhibits genetic polymorphism in all populations examined to date. By isoelectric focusing and immunoblotting, three common alleles have been demonstrated in 365 unrelated Nigerian blacks. Furthermore, the APO E genetic polymorphism's effect on quantitative levels of lipids and lipoproteins has been determined. The respective frequencies of the APO E*2, APO E*3, and APO E*4 alleles are .027, .677, and .296. The effect of APO E polymorphism is significant only on total cholesterol and low-density lipoprotein cholesterol. The average excesses of the APO E*2 allele are to lower total cholesterol and low-density lipoprotein cholesterol by 9.19 mg/dl and 11.11 mg/dl, respectively. The average excesses of the APO E*4 allele are to increase total cholesterol and low-density lipoprotein cholesterol by 5.64 mg/dl and 6.18 mg/dl, respectively. On the basis of the differences in (a) the distribution of APO E allele frequencies between the Nigerians and other populations and (b) dietary lipids, we propose a model that shows that lipid metabolism is influenced by the combined effects of the APO E polymorphism and environmental factors.     

Genetic studies of low abundance human plasma proteins. III. Polymorphism of the C1R subcomponent of the first complement component.

Genetic polymorphism of the C1R subcomponent of human complement component C1 has been detected in normal plasma samples using the high resolving power of isoelectric focusing in 6 M urea followed by immunoblotting. There are two common alleles at the C1R structural locus that show autosomal codominant inheritance. The C1R*1 and C1R*2 allele frequencies in U.S. white and U.S. black blood donors are: .934, .066, and .899, .101, respectively.     

Distribution of AB0 and RH blood group alleles in different populations of southern Punjab, Pakistan.

The analysis of a sample of 1632 individuals from patients of the Nishtar Teaching Hospital, Multan, suggests that different ethnic groups (Araeen, Mughals, Syed, Jat, Rajputs, Baloch and Pathan) are not significantly different from another with regard to the distribution of RH blood group alleles (RH*d around 0.30). The distributions of the AB0 blood group alleles suggest that different ethnic groups are not significantly different from the average alele frequencies (AB0*A = 0.23, AB0*B = 0.33, AB0*0 = 0.47) except for the Pathan ethnic group (AB0*A = 0.35, AB0*B = 0.47, AB0*0 = 0.27). The populations of different geographic areas are not significantly different from the average allele frequencies, except for the southern district of Rahim Yar Khan (AB0*A = 0.12) and the northern district of Sahiwal (AB0*A = 0.19). The populations of Sahiwal (RH*d = 0.35) and Muzaffargarh (RH*d = 0.36) yield significantly different allele frequencies at the RH locus. The interpopulation differences can be explained by the geographic distance. There is a significant difference in the frequencies of the AB0 alleles between rural and urban populations, suggesting that rural populations maintain their isolation from urban populations. Rural and urban populations are not significantly different from one another concerning the allele frequencies at the RH locus.     

The plasminogen polymorphism in South African Negro populations: genetics and anthropogenetics

Summary Genetic polymorphism of human plasminogen (PLG) was investigated in 1252 unrelated individuals from eight South African Bantu-speaking Negro tribes. PLG phenotypes were determined by isoelectric focusing (pH 3.5–9.5 and 5–8 gradients) of neuraminidase-treated samples and subsequent detection by caseinolytic overlay or immunoblotting with specific antibody. No significant difference in the distribution of PLG alleles among the eight ethnic groups was observed. The combined allele frequencies of the common alleles in South African Negroes were 0.6977 for PLG*A, 0.2736 for PLG*B. In addition, six rare alleles were seen: PLG*A3, *A1, *M2, *B1, *B2, *B3. The rare variant PLG*B2 was proven to segregate by autosomal Mendelian inheritance in a family. The combined frequency for the rare alleles was 0.0287. The distribution of phenotypes in the total population sample was found to be in Hardy-Weinberg equilibrium. A striking difference in PLG allele distribution between Negroes from South Africa and published Negroid frequencies from North America could be observed. This difference was also seen in comparison with Mongoloid populations; in contrast, PLG frequencies for South African Negroes were similar or almost identical to known Caucasoid distributions.